Youtube can let user upload the viedos that they want to share on the internet, that means that Youtube is a good channel for the company to place there virals here.
SamGNN's is a big forum about games in Taiwan. They let people share the comments on the forum and also provide some news about games to let people discuss in and create voices.
Because of that, SamGNN create a Youtube Channel on Youtube to let people subscribs in, let them to get the news immediately and discuss about the topics on the forum. And through this Youtube Channel, SamGNN can know more about hers subscribers and increase hers name about "Games Forum", not only in Taiwan district, but also internation games players.
p.s. She just provide chinese version forums, so may be pan-Asian.
Source: http://www.youtube.com/user/SamGNN